The present invention generally relates to processing effects for wide-angle images. More particularly, the present invention relates to special effects processing that provides image portion replacement for wide-angle video images, shifted image portion replacement for wide-angle video images and other special effects for wide-angle video.
A goal of imaging technology is to make the observer feel as though he or she is part of an image. U.S Pat. Nos. 5,990,941 and 6,002,430, currently assigned to the assignee of the present application, describe wide-angle image viewing systems and methods. The patents provide full freedom viewing inside of a complete spherical image composed of one or two combined hemispheric images. As a result, there are no bounds on the user""s freedom to view in any direction.
U.S. Pat. No. 6,002,430 patent discusses techniques for capturing first and second images, each having a field-of-view of 180 degrees or greater. In one embodiment two cameras are placed in a xe2x80x9cback-to-backxe2x80x9d arrangement having lenses with a 180 degree or greater field of view (e.g., fisheye lenses). An imaging element or elements capture the images from each lens. The captured images are seamed together to form a single spherical image. Also, U.S. Pat. No. 6,002,430 patent includes a viewing engine that provides a real-time interactive image window that can be directed anywhere in the spherical image. Preferably, a personal computer system runs perspective correction algorithms to create the image window. Other wide-angle viewing systems are known, but known systems generally do not provide special effects for wide-angle video images.
Reber et al., in U.S. Pat. No. 5,706,421, discloses placing an animated character in a wide-angle image. An animated character generator superimposes the animated character onto a perspective corrected image in a spherical wide-angle image. However, the animated character is over-laid on the spherical image, and the Reber et al. does not disclose performing special effects on non-perspective corrected images in wide-angle video images.
Special effects can be used to enhance the quality of video images and a need exists for providing special effects for wide-angle video images.
An aspect of the present invention is to provide an apparatus and methods that provides special effects for wide-angle video images.
In accordance with the principles of the present invention, a method is provided for capturing wide-angle video that includes a plurality of sequential frames, each frame having at least one wide-angle image, and replacing a portion of at least one of each wide-angle image in at least one of the frames with a replacement image. The step of replacing a portion of at least one of each wide-angle image includes replacing the portion with a portion of a wide-angle image in a second frame captured subsequently to the frame having the replaced portion. The portion of the image in the second frame may have the same shape as the replaced portion and represents an unobstructed view of the surrounding environment. Alternatively, the step of replacing a portion of at least one of each wide-angle image includes replacing the portion with a planar image that is warped to the same curvature of the replaced portion and has the same shape as the replaced portion.
In accordance with the principles of the present invention, an apparatus is provided that includes a wide-angle video image capture device that captures wide-angle video in a plurality of sequential frames, each frame having at least one wide-angle image, and preprocessing circuitry that receives digital wide-angle video images of the at least one wide-angle image in each frame and replaces a selected portion of at least one of each wide-angle image in at least one of said frames with a replacement image. The replacement image includes a selected portion of a wide-angle image in a second frame captured subsequently from the frame having a replaced portion. The selected portion of the replacement image has substantially the same shape as the replaced portion and represents an unobstructed view of the surrounding environment. Alternatively, the replacement image is a planar image warped to the same curvature and having the same shape as the replaced portion.
In accordance with the principles of the present invention, a method and apparatus is provided for performing image-intensity scaling. A wide-angle video image is divided into a plurality of areas. An adaptive threshold, associated with the average image intensity of pixels in each area, is calculated for each area. The intensity of a pixel in at least one of said areas is compared to the adaptive threshold for the area. The pixel intensity is adjusted, when the intensity is not equal to the adaptive threshold.
In accordance with the principles of the present invention, a method and apparatus is provided for detecting and removing flare. Preprocessing circuitry compares the change in intensity of pixels in each row of at least one wide-angle image in each frame to two threshold values to detect flare, and adds pixels in each frame to remove the detected flare.